Slim laptop and netbook manufacturers will be getting a bit more breathing space inside those tiny cases early next year thanks to Seagate.

Typically the choice for a hard drive inside slim or small laptops is between 1.8″, 2.5″ or SSD drives. SSD brings with it a price premium, 1.8″ drives limit storage, and 2.5″ drives take up more space.

But Seagate is set to unveil a new 2.5″ drive on January 5th that trims the thickness of the drive from 9.5 mm to just 7 mm. It may not seem like much, but that’s a space and weight saving while retaining the same levels of storage.

Robert Whitmore, chief technology officer at Seagate, said:

Finally, we have now started the qualification process of the industry’s first 2.5 inch 7 mm high hard disk drive. This new slimline product allows our OEM customers to continue to reduce the thickness and weight of their notebook platforms.

The drive will be on display at CES starting January 7th and is expected to form part of Seagate’s Momentus Thin series. No pricing or availability dates have been announced yet.

2.5 mm isn’t very big, but when you start with 9.5 mm as a standard size it’s massive. The savings this new drive could bring from production through to end user are considerable.

This drive is thinner and lighter meaning Seagate can ship more of them for less allowing for slightly larger profit margins. In the hard drive market profit margins are very slim so every little helps. Manufacturers can then use the space saved to either offer a slimmer laptop, or use the space for something else. Those laptops will also register ever so slightly lighter on the scales.

2.5″ drives seem to be the sweet spot for mobile storage at the moment. There are price and storage limits associated with the alternatives mentioned above. I don’t think that will change until SSD prices come down significantly at which point they will likely replace 2.5″ drives as the main choice in most laptops. The reduced power requirement and speedier access make SSD a winner, but for now it remains the premium option.